Hello, World
by KHB123
Summary: Itachi loves Sasuke more than anything. His little brother is his whole world. His light. His salvation. He has been from the moment he was born. That is why Itachi is willing to protect him no matter what. (Rating may change) (Non-Yaoi)


**This is originally supposed to be a one-shot, but I'll keep it open for more options and random one-shots in the future.**

 **Itachi and Sasuke are my favorite brotherly love fanfic:), but just so you know…..I can read Yaoi and Uchihacest, but I don't do it, so don't expect any in the future.**

 **Here, Itachi is six years older than Sasuke instead of five.**

* * *

On his toes, Itachi crept through the hallway of the manor.

Fugaku and Mikoto were deep sleepers, but even then, they could not have sensed him. He had long learned to control his chalkra since the age of four, which was not too long ago. Every night they come back...the nightmares.

Tonight, he had been back in a village lit with fire, the streets scattered with corpses and the ground pooled with blood. The blood of people, innocents and shinobi alike. The kunai was back in his small hand, also bathed in blood from the many lives it had taken to survive this war.

This was his nightmare. His worst memories. Itachi witnessed the horrors of war all his young life, trained since the age of two, and became a killer at the age of four.

It was all he had ever known. War and death...training and cold logic...

...until at the age of six, going on seven, Itachi held _him_ for the first time. On the day of his birth.

When the Uchiha prodgiy looked upon the tiny face of his baby brother, his whole world had changed.

Itachi said hello to Sasuke Uchiha, and he finally discovered, for the very first time, what it was like to truly know happiness.

.

.

.

 _(2 weeks ago)_

In the Konoha hospital, there were white walls everywhere. They looked clean, but Itachi knew better. They were probably deceptively washed from germs, increments, and blood.

Blood.

He imagined it splashed against those white walls while hearing Mikoto's moans and screams echoing from behind the door to his left down the hall.

Itachi sat up straight in his seat, rigid and blank-faced, hands folded in his lap.

They were clenched tightly.

In appearance, he was composed and waiting patiently with Fugaku sitting next to him with his arms and demeanor calm. He had been in the room before with his wife, but in the end, when it had already been thirteen hours of labor, he ended up out here with his son. Sometime he would get up, pace, and would sit back down with nothing more than a low grunt. The cycle would just repeat.

Itachi didn't understand. He wanted to demand why he wasn't in there with Mikoto, but as usual, held his tongue and remained silent.

Anyone who would have passed by, especially the children his age, more or less, would have looked at him strangely. Even a little bit fearfully. He was, after all, more a machine than a child. Cold and emotionless on the outside as well most of the inside, with a brain that far surpassed the average IQ of a six year-old. Maybe even an eighteen year old, or possibly more. A true, talented, perfect Uchiha genius of his clan.

But really Itachi was afraid. Each time he heard her screams of pain, the nightmares would flash unwillingly before his steady eyes. Blood, bodies, blades, torture, death...Itachi was used to it, but he still hated it more than anything. Worse that he should hear his own mother scream in such agony and there was nothing he or his father could do except wait for it be over.

What if something happened to her...and his baby sibling?

Finally, Mikoto's screams ceased. There was a long pause that paused Itachi's breath as he listened to the chakra signatures on the other side. He could sense the drained remains of chakra from his mother, the nurses, and...a small, fresh new one. Warm and fluttering with life, but weak.

His heart sped up. Could it be...?

The door opened and a nurse appeared with a smile.

"Fugaku Uchiha, you have a son. A healthy baby boy."

"Hn."

Itachi felt his large hand touch his small shoulder briefly, "Wait here," before the patriarch went inside. Itachi thought he felt it tremble slightly, the only sign that meant his tousan was as worried as he was.

He obeyed and remained seated while Fugaku followed the nurse inside.

After about a minute, Itachi waited, feeling the movements of the chakra signatures inside, wondering if they were going to call him in yet.

Finally, Itachi got up from his seat and just walked toward the door, which was slightly open a crack. Inside, he can hear the unmistakeable wailing of an infant. It must be the new baby. The little person from his kaasan's stomach that he had waited to meet all these months.

 _I'm...a big brother._

His gut fluttered with the unfamiliar notion of nerves.

Itachi didn't know what these storm of feelings that he kept hidden. Excitement? Nervousness? Wariness? That had been like that for the past eight months since he learned that there would be a new member in the family. Itachi Uchiha knew how to be a prodigy, an obedient son, a killer, all at his early age...but how does one be a big brother?

The only role model Itachi had for that part was Shisui, who had been a big brother to him in every way, who had been his training partner, his brother-in-arms, and best friend who joked around him, teased him, comforted him, and even showed his excitement and pride that his younger cousin was going to be a big brother...but even now, after all that Shisui was to him, it was still alien to the young prodigy.

What if...What if he wasn't good enough? What if his new sibling hated him? Looked at him strangely like the other kids?

 _What if I...scare him?_ Itachi didn't like that thought. Not one bit. He felt very nervous.

Mikoto was in the bed where Itachi last seen her, all tired and sweaty with her black hair pulled back except for some wet loose strands struck to her pale face, but she was _glowing_.

Fugaku was seated next to the bed, and Itachi was slightly shocked to see the faintest of smiles on his own face as the boy watched him hand over a tiny blue bundle back to his wife. The loud wailing still followed and Itachi can see two tiny hands appear briefly as his kaasan hugged the bundle to her chest, shushing it softly while running a finger over the hidden face.

Cautiously, Itachi entered the room quietly and walked closer to the bed, both concerned and curious.

"Itachi, come here," whispered Mikoto, holding out her free hand. "Come here..."

Itachi took her hand and sat carefully onto the bed beside his mother. He can see a tiny set of spiky black hair in the bundle.

"Itachi, this is your baby brother," she whispered with a smile. Her hand moved aside a flap to reveal a tiny, pink face. "This is Sasuke."

Itachi's eyes widened as they laid upon his face for the very first time. It was scrunched up in a pout full of tears as he bawled, his cheeks round, soft, and pink, his fuzzy hair black and spiky, and his tiny hands curled against his tiny body.

 _He's so tiny..._

Itachi lifted a hand and brushed his fingers against the baby's unblemished cheek with the softest touch, before trailing them across his soft, spiky hair.

The baby had stopped crying, letting out a small whimper. When his sleepy eyes opened a crack, they were dark and shiny, like every Uchiha, but with pure innocence and light that were so new. So curious...so helpless...looking right at him.

This little baby, his otouto, he was...the most beautiful thing Itachi have ever seen.

 _Sasuke._

"Would you like to hold him?"

Itachi blinked and shut his mouth, which had been gaping in awe without his realization. Hold him? He gulped, but nodded, trying to ignore the fact that he was shaking.

Was he really that afraid? Of a tiny newborn baby? Of himself?

 _What if I break him, his perfect little body?_ he thought, feeling panic ice his veins. _What if I scare him and make him cry again? What if I..._

The infant was carefully shifted in his arms, his hand instinctively moving to support his head with his kaasan's help.

Itachi held his breath when he held his baby brother, never taking his eyes off of the little miracle lying safely in his arms. He was so light and warm, so fragile, as if he were made of glass, his little heartbeat fluttering beneath the elder's arms. Those sleepy eyes looked back up at him with an equal amount of awe and curiosity. Then Sasuke started to yawn, making a little sound as he did. He was really, really cute.

Something large swelled in Itachi's entire chest. It was so overwhelming.

Tears were running down his face.

"Itachi, get a hold of yourself," muttered Fugaku. It was unbefitting that his hardened prodigy turn into a blubbering mess.

"Sweetheart, are you alright?" Mikoto asked, running a hand over her eldest son's hair soothingly. "What is it?"

Itachi shook my head and sniffed, feeling embarrassed. Why was he crying? He wasn't feeling sad. Not one bit. But this feeling was so big and so overwhelming that he didn't recognize it.

He had never reacted like this before. Not even during the war.

"I don't know, Kaasan," Itachi said softly. "I'm sorry. I don't know what's wrong with me. I don't feel sad, but I can't stop..." Itachi hugged his baby brother closer, but carefully, feeling his lips quirk upwards while his body shook. His skin was flushing and his heart was beating so fast.

Itachi felt like at any moment he could hyperventilate. Was the baby in his arms really the cause of these feelings, these reactions? He should give the newborn back...but that was the very last thing he wanted...Itachi never wanted to put him down, feeling that it was safer in his arms than anywhere else.

"Oh, Itachi." Mikoto giggled and wiped a tear from his eye with her thumb. "There is nothing wrong at all, dear. You're just...happy. Very happy." She could not recall the last time, if ever, that her firstborn had been this emotional. For some reason, it made her glad, no matter what her husband thought.

 _Happy?_

Happy is when hanging out with Shisui, happy is when getting away from the bloodshed, happy is when your father stops lecturing you for a few minutes about duties or that your mother can attempt to treat you like a normal kid, or a normal son... To Itachi, happy was merely moments of satisfaction in life.

When Itachi gazed down at his little brother, he could actually feel a real smile on his face when the baby's eyes continued to look back up at him with such calmness and trust that it was hard to believe.

He must look ridiculous, but Itachi couldn't bring himself to care. His infant brother's tiny hand latched onto his finger and he cooed happily, making Itachi gasp out a chuckle in response.

If this was true happiness, then it was wonderful. Strange and new, and a little scary...but wonderful. Amazingly wonderful.

This became the happiest day of his life.

For once, the young prodigy forgot all the memories of war, bloodshed, and death...now replaced with a warm, miraculous light that now curled up in his arms.

Everything now made more sense. Everything began with this little newborn that was his little brother. _Everything._

Itachi felt the instant and strong _need_ to protect his little otutou. Nothing else mattered more than that. He could no longer remember his life without his new sibling.

 _"Sasuke,"_ Itachi whispered the chosen name, as he reached up to take his longer hair strands. "Hello, otouto. I'm Itachi, your niisan. You don't have to worry, Sasuke. Your niisan is going to take care of you always. I promise."

While Sasuke played with his hair strands, Itachi leaned down and kissed the top of the little one's head, receiving a happy coo in response.

.

.

.

 _(Present)_

Itachi entered the nursery and quietly approached the crib.

The sight of his baby brother, who slept quietly on his back in the crib with a blue blanket pulled halfway up his chest, made him breathe more easily.

Mikoto must have managed to calm his loud crying earlier. Usually, whenever Itachi got to hold his brother, Sasuke calmed down the most when receiving his warmth. It was obvious that the newborn had already loved his big brother, since he was always happy, trusting, and calm around the elder boy. This time, Mikoto did the honors and was proud of herself tonight, finally able to get some sleep.

But Itachi, as always, didn't sleep well. He had another night terror. One of murder and blood, still scaring him to this day and making him scream awake.

While having spent the past ten minutes trying to calm his heartbeat, Itachi felt the desperate urge to check on his brother again. A part of him alway felt afraid that his night terrors would come to life and start attacking his helpless little brother. He had then felt the need to protect Sasuke from all the nightmares and monsters.

While sleeping, Sasuke's little hands splayed on either side of his head and his lips slightly parted that allowed rapid wisps of tiny breathing from beneath his tiny, delicate nose.

Kneeling there, one hand wrapped a bar, Itachi's other hand reached in and swept over the infant's soft, soft black hair that carried a tiny hint of blue. Fingers trailed across his smooth, round cheek, feeling his breath beneath his tiny nose like the rise and fall of his puny chest.

So small...so vulnerable...

So peaceful...

So perfect...

A soft smile touched his features as Sasuke's light fingers brushed his own.

Then, they instinctively closed around his pinky finger. Itachi's heart ached with such a tenderness he had always felt since he first held his otutou.

 _Sasuke._

Itachi watched him sleep with half-closed eyes, feeling peacefulness and love like he had never felt before. The elder brother never left his otouto's side the entire night. His eyes began to drift to sleep as he watched Sasuke's tiny, perfect form sleep with his face turned toward him.

 _You make up my whole world._

So beautiful...Itachi slowly closed his eyes and fell into a dreamless sleep.

 _Sleep well, my precious otutou. I will watch over you. I will always keep you safe. Always._

* * *

The next morning, a newly awakened Mikoto stood at the doorway, seeing his eldest child leaning against the crib where the newest Uchiha member still lay, both sleeping peacefully for the first time. Young, stoic Itachi was not sleep-deprived from night terrors and baby Sasuke not awake and crying with restlessness.

The infant's hand was still wrapped around his nii-san's pinky finger, still deeply asleep.

 _My precious boys._ Mikoto smiled. She went to kneel down, kissing the top of Itachi's head and brushing a hand over Sasuke's tiny one, careful not to wake them.

The world was indeed brighter when those two were together.

* * *

 **Otouto= little brother**

 **Niisan= big brother**

 **Tousan=father**

 **Kaasan=Mother**


End file.
